The chairman and managing director of GM's Australia subsidiary, Holden, Peter Hanenberger, who is also a General Motors group vice president, will retire on January 1 after 45 years of service. Denny Mooney, executive director of vehicle integration for GM North America Engineering, will succeed Hanenberger as Holden chairman and managing director. He will join Holden later this year and work with Hanenberger to ensure a smooth transition.